Answer:
x = 3 and x = -12
Step-by-step explanation:
To solve an absolute value equation, you create two equations, one where the right side is negated and one where the right side isn't:
| 2x + 9 | = 15 becomes:
2x + 9 = 15 and 2x + 9 = -15
2x = 6 and 2x = -24
x = 3 and x = -12
Why this works is that |-x| and |x| will both be equal to 0. Remember that absolute value is the distance a number is away from 0.
Answer:
the answer is 5
Step-by-step explanation:
Proof by induction
Base case:
n=1: 1*2*3=6 is obviously divisible by six.
Assumption: For every n>1 n(n+1)(n+2) is divisible by 6.
For n+1:
(n+1)(n+2)(n+3)=
(n(n+1)(n+2)+3(n+1)(n+2))
We have assumed that n(n+1)(n+2) is divisble by 6.
We now only need to prove that 3(n+1)(n+2) is divisible by 6.
If 3(n+1)(n+2) is divisible by 6, then (n+1)(n+2) must be divisible by 2.
The "cool" part about this proof.
Since n is a natural number greater than 1 we can say the following:
If n is an odd number, then n+1 is even, then n+1 is divisible by 2 thus (n+1)(n+2) is divisible by 2,so we have proved what we wanted.
If n is an even number" then n+2 is even, then n+1 is divisible by 2 thus (n+1)(n+2) is divisible by 2,so we have proved what we wanted.
Therefore by using the method of mathematical induction we proved that for every natural number n, n(n+1)(n+2) is divisible by 6. QED.
